EPA blocks mine project that threatened crucial Alaskan salmon runs

The Environmental Protection Agency moved to block the Pebble Mine in Alaska on Tuesday, preventing mining waste discharges into the Bristol Bay watershed.

It’s a decision the agency says will preserve the thriving ecosystem and safeguard Alaska’s sockeye salmon fishery, which produces about half of the world’s harvest of the species. Sockeye is the most valuable Alaska salmon fishery.

“The Bristol Bay watershed is a vital economic driver, providing jobs, sustenance and significant ecological and cultural value to the region,” EPA Administrator Michael Regan said in a news release.

The decision could put an end to a heated, yearslong debate over the massive mining project as government agencies vacillated over the watershed’s future and political winds changed. It could also have had profound consequences for Alaska’s economy, which is reliant on both salmon and mining.

The decision also delivers on a campaign promise: President Joe Biden during his election run said that Bristol Bay’s headwaters were “no place for a mine.”

The decision is another major setback for mining developers who have been exploring the development of a gold, copper and molybdenum mine at the headwaters of the Bristol Bay watershed since 2001. The project would have mined about 1.4 billion tons of ore over 20 years, according to the Army Corps of Engineers. If approved, the project would generate tens of millions in tax dollars for the state of Alaska.

The mine developers have called it the “world’s largest undeveloped” resource of copper, gold, molybdenum, silver and rhenium.

Bristol Bay boasts incredible wild salmon runs, when fish migrate back to freshwater from the ocean. The pristine watershed produces the largest run in the world of sockeye salmon, according to analysts with the McKinley Research Group. This year, forecasters expect a sockeye run of about 50 million fish. Bristol Bay salmon fisheries contribute more than $2 billion to the U.S. economy and more than 15,000 jobs, according to a 2021 McKinley report prepared for the Bristol Bay Defense Fund, a group that opposes the mine. Tribal communities rely on Bristol Bay salmon for subsistence harvest.

The surface mine would have operated for 20 years and then required about 20 years of work to close it, according to the Corps, which separately denied the mine developers a permit in 2021. Water management and monitoring would have been needed for centuries. Its decision remains under appeal.

Dissolved metals, and in particular copper, can be dangerous for salmon. Copper can disrupt the salmon’s olfactory system and change fish behavior, according to a review of research on mining’s impacts on salmon in the journal Science.

The EPA action under the Clean Water Act specifically prohibits discharges of dredged mining waste into the North Fork Koktuli River and the South Fork Koktuli River. The agency said the mining project would result in the total loss of 100 miles of streams that are salmon habitat and have other negative effects downstream. More than 2,100 acres of wetlands would be lost.

“After reviewing the extensive scientific and technical record spanning two decades, EPA has determined that specific discharges associated with developing the Pebble deposit will have unacceptable and adverse effects on certain salmon fishery areas in the Bristol Bay watershed,” EPA Assistant Administrator for Water Radhika Fox said in an agency news release.

The Pebble Limited Partnership, which has been developing the mining plan, criticized the EPA, accusing it of exceeding its authority under the Clean Water Act, saying that it is harming Alaska’s economy and missing an opportunity to mine copper that will be critical for the energy transition. The EPA's move sets up a potential legal challenge.

"This preemptive action against Pebble is not supported legally, technically, or environmentally. As such, the next step will likely be to take legal action to fight this injustice," CEO John Shively said in a statement.

The fate of the Pebble Mine has seesawed with incoming political administrations. First, the Obama administration proposed a determination that would have prevented the mine’s development. Later, the Trump administration withdrew that action and urged the mine developers to resubmit their proposal.

“There was a lot of back and forth. This is the first time we have a final determination under the Clean Water Act” for the Pebble Mine, said Hannah Perls, a staff attorney at Harvard Law School's Environmental and Energy Law Program.

The Biden administration signaled that Bristol Bay was a priority for review when the president took office, and that process took two years. Perls said that timeline suggests the administration was moving deliberately, building a scientific case and preparing for that legal challenge.

Reversing the final determination and getting the project off the ground would most likely require several steps and for the mine developers to surmount significant legal and political hurdles, Perls said.

Environmental groups and tribal governments in the Bristol Bay watershed cheered the EPA's decision, saying it preserved a pristine landscape and preserved a way of life that depends on salmon.

"EPA’s action today helps us build the future where our people can remain Yup’ik, Dena’ina, and Alutiiq for generations to come," said Alannah Hurley, the executive director of the United Tribes of Bristol Bay.

This article was originally published on NBCNews.com